INTRODUCTION Xxix 



can be traced from Shrh'enham and Faringdon, and thence eastwards 

 in a belt about three miles wide as far as Abingdon. 



On this formation are the extensive bogs of Cothill and Frilford, 

 and the flora contrasts very favourably with that of the Oxford Clay. 

 Potamogeton coloratus, Carex xanthocarpa, C. Boenningnausiana, Sedum dasy- 

 phylhim, Rosa agrestis, and Cotyledon Umbilicus appear to be confined to this 

 formation. A conspicuous plant is Clematis Vitalba, which is rare or 

 absent from the Clays. Characteristic species are Criicus eriojjhorus, Arena 

 pubescens, A. pratensis, Bromus eredus, Brachypodium pinnatum, Astragahis 

 glycyphyllus, Viola hirta, Orchis pyraynidalis, Cerastium arvense, Picris Hier- 

 acioides, Poterium Sangiiisorba, and Lithospermum officinale. 



Among the other local plants found on it are Anemone Pulsatilla, 

 Hypopitys, Trifolium arvense, T. scabrmn, T striatum, T. medium, Lathyrus 

 Nissolia, L. syhestris. Genista tinctoria, Rubiis ihyrsoideus, R. pubescens, 

 Geranium pyrenaicum, G. rotundifolium, Sisymbrium Sophia, Arenaria tenui- 

 folia, Cnicus pycnocephalus, var., Aiiemisia Absinthium, Onopcrdon, Carum 

 segetum, Calamintha montana, C. parvipora, Mentha piperita, M. longifolia, 

 Myosotis collina, M. versicolor, Campanula glomerata, Polygonum dumetorum, 

 Festuca Myurus, Ceterach, Asplenium Irichomanes, A. Adiantam-nigrum, 

 Lilium Martagon, and Orchis ustidata. 



The Kimeridge Clay consists of dark shaly clay, with nodules 

 of earthy limestone often septarian, bands of impure limestone, selenite, 

 and pyrites. It forms a tract of flat unpicturesque country, with 

 a stiff, cold, damp soil. In the west of the county it forms flat, wet 

 fields about Shrivenham, and extends as far as to Longcott : then it is 

 concealed by the Faringdon sponge-gravels of the Lower Greensand, 

 and owing to the unconformity of the representatives of the Cretaceous 

 and Oolitic formations, the Lower Greensand strata rest directly upon 

 the Coral Bag. The Kimeridge Clay reappears on the east side of 

 Coles' Pits (which were once supposed to be an ancient British 

 village) and then stretches as a band of varying width (1-3 miles), 

 principally on the south side of the river Ock, as far east as Sutton 

 Courtney. It in fact forms the level and rather uninteresting country 

 in the centre of the Vale, the fields of East and West Hanney, 

 Steven ton, and Drayton. At Abingdon and near Marcham it crosses 

 the Ock and extends northwards to Radley, Sunningwell, and Bagley 

 Wood, and forms a zone round the eminences of Boar's Hill and 

 Cumnor. A similar but narrower belt almost surrounds Faringdon 

 Clump, but on the south-eastern side it thins out and eventually dis- 

 appears. Many large fields, separated from each other by watery 

 ditches, aie found to occupy a considerable portion of the formation, 

 which is poor in botanical features. Senecio erucifolius, Picris Echioides. 

 and Bipsacus sylvestris are found abundantly, and Apium nodiflorum, Siuni 

 eredum, Epilobium hirsutumj E. parvijlorum, and Pulicaria dysenterica are 



